This invention relates to labeling machines, and more particularly to a roll feed labeling machine for applying individual labels severed from a roll of such to individual articles such as containers.
In recent years, greater use has been made of labeling machines capable of severing individual labels from a roll of like labels, and applying them to articles, frequently containers. In normal practice, the like labels are joined continuously in a band for rapid, non-stop, dependable operation of the labeling machine. Any discontinuities in the repeat pattern of like labels are normally undesirable, their presence being conventionally detected by suitable sensing means which deactivates the machine to allow resetting by the operator. Although such discontinuities due to web splicing, faulty printing or the like are somewhat unavoidable, great efforts have been taken to avoid printing processes which by their nature cause repeat printing discontinuities as an inherent result of the printing process. Thus, the repeat label pattern of a web is normally printed by letter press, rotogravure, or flexographic press, or the like, to cause a continuous repeat pattern. Offset printing has been avoided because it produces a repeat scrap or blank space of different dimension than that of the labels, and at frequent intervals along the printed web or tape.
Yet, it has been determined that offset printing for labels for pharmaceutical containers or the like would be particularly advantageous because of the high quality of printing, because of the ability to couple an offset printer with the labeler to effect a complete interrelated printing and labeling set up, because offset printing plates are relatively inexpensive to produce, and because offset printing ink is readily available, among other reasons. However, as noted above, offset-printed tapes produce periodic non-print scrap areas caused by the zone of the printing cylinder where the peripheral printing plate ends are joined together, causing serious production problems in conventional labeling machines.
The labeling of pharmaceutical containers also involves the critical process of verification of the labels. That is, each individual label must be checked in a manner to insure that its application only to a container of one particular substance, or else disastrous results can occur. This verification process can be conducted by using a particular identifying code on each label. Some systems of coding necessitate cut-out portions of the label tape, which are correlated with cooperative reading means, others use printed codes on the tape, and still others use both. The printed type is more desirable because it can be applied at the same time the other information is printed on the label, and requires no separate die-cutting process or the like. If offset printing could be used, however, the code indicia marks could be relatively small to be inconspicuous, and yet have high quality with very distinct boundaries and accuracy of location on the label.
Even with accurate code indicia printing, however, the present process of verification can yield improper results. As is known in the art, verification conventionally uses inspection or "reading" of the individual label code while the label is still on the tape so that the position of the web and each code symbol can be accurately held during inspection as by a photoelectric sensor. After being so-checked, the label is then fed to the cutter, severed from the tape, transferred to the applicator, activated as by heat to be adhesive, and applied to a container. Obviously, the label after being "cleared" by the verifying equipment, can become mishandled, doubled with another label, dropped, distorted, misapplied, or otherwise improperly treated in these subsequent steps so that, even though already cleared, is not properly applied to the appropriate container, to the great potential detriment of the ultimate user and the pharmaceutical company held responsible by law. Such mishaps also can prevent the pharmaceutical company representatives from being able at the end of an operational run, to properly account for the required correlation of number of labels with number of containers fed to the labeler, number of containers discharged from the labeler, and number of rejects.
These and other related problems are encountered with conventional labeling machines that require the continuous attention of an operator at the higher operating speeds.